Explorations deep in the Atlantic Ocean have uncovered what scientists believe are new species of tiny wing-footed snails, pulsing jellyfish and swimming worms in plankton.

The zooplankton species were discovered as researchers charted plankton to see if climate change is harming the base of the food system in the sea, and if acidification in the ocean is affecting sea life, scientists reported Thursday.

Oxygyrus keraudreni uses its flat feet like a paddle to push through the water.
(Courtesy of Russ Hopcroft, University of Alaska Fairbanks)

Plankton, the microscopic plant and animal organisms that drift in seas, oceans and lakes, helps to moderate climate by taking carbon to the bottom of the water. Oceans absorb carbon dioxide, but the process increases the amount of acidity in the water, which could make it more difficult for creatures like crabs to grow shells.

Fish and marine mammals, such as whales, feed on plankton. 

More than two dozen marine scientists from 14 countries, including Canada, were on board for the 20-day survey of tropical waters between eastern United States and the mid-Atlantic ridge, including in the Bermuda Triangle, .

Streetsia challengeri lives in and on jellyfish and related animals.
(Courtesy of Russ Hopcroft, University of Alaska Fairbanks)

They found "what appear to be several undescribed species that may well prove new to science," said the expedition's scientific leader, Peter Wiebe, senior scientist at the Woods Hole Oceanographic Institution in the United States.

"It was tremendously exciting, the sense of discovery," Wiebe told Canadian Press. "There was huge excitement because people had not seen animals this size from these depths."

Samples were collected from the deepest waters of the ocean, down to 5,000 metres.

They are also studied DNA from the zooplankton, the animal component of plankton, completing in three weeks what once took years in the lab.

New species include:

• Six types of ostrocods, shrimp-like creatures that kick their tails and are preyed on by commercial fish species.
• Swimming worms.
• So-called flying snails called pteropods. The creatures propel through the water by flapping  two wing-like lobes on their feet. 
• Pulsing jellyfish. 

The animals are usually millimetres long, but some, such as jellyfish, can range up to the four centimetres in length.

The U.S. National Oceanic and Atmospheric Administration funded the study, which is part of the wider Census of Marine Life, a project to map the ocean life by 2010.